A multi-wavelength study of IRAS 07427–2400 in line and
continuum emission was conducted to investigate the nature of a H2–0 S(1) line emitting feature around this ultra-compact HII
region. High resolution 3.6 cm continuum observations from the Very
Large Array and 350 μm continuum observations from the Caltech
Submillimeter Observatory, combined with archival far-infrared data of
IRAS 07427–2400 show a flux density distribution indicating a
luminous () point source associated
with an ultra-compact HII region. A Grey body model fit to the flux
density distribution yields a dust emissivity index
() indicative of a circumstellar disk/envelope. Our
C18O map shows a dense core centered on the continuum source,
with the major axis roughly aligned with the H2 feature. A
position-velocity diagram of the C18O core obtained along the
major axis shows rotation with a velocity gradient of
~0.1 km s-1 arcsec-1. New CO –2 maps of the
region are presented which reveal a massive molecular outflow from the
IRAS source. We argue that the H2 feature arises in a
disk/envelope around IRAS 07427–2400 and not in an outflow. We
present a near-infrared HK band spectrum of the H2 features that
shows several ro-vibrational emission lines of H2 and [FeII].
Analysis of the line ratios indicates that the line emission is
shock-excited and not due to fluorescence. We estimate an excitation
temperature of ~1600 K and an average extinction of
mag to the H2 feature. The line fluxes yield a mass
accretion rate of yr-1 and a lifetime of
~53601200 yr resulting in a disk/envelope mass of
14050 . The resulting Jeans Mass of 2420
indicates that the disk/envelope will not undergo fragmentation.
IRAS 07427–2400 represents one of the most massive YSOs known to date
forming by means of accretion.

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